Starting with your form intersections, your work here is generally coming along pretty well. The one thing I want to draw to your attention is the intersection between the cylinder and box towards the bottom right of the page. While this is actually very close to correct, the piece that is missing is that the intersection line itself suggests that the curved surface of the cylinder is intersecting with a plane that is set at a much steeper incline, and so it comes off the surface of the box. Be sure to consider the angle of both intersecting surfaces, as they both come into play when determining the particular orientation of a given intersection line.

Continuing onto your cylinders in boxes, it appears that you may have rushed ahead into this one without adequately reviewing the instructions - specifically the instructions on how the line extensions are to be applied, as you appear to have only put down lines to extend the boxes' edges, and the minor axis lines of each ellipse, but not the contact point lines. Be sure to review those instructions so you're aware of exactly what it is you're being asked to do. While it's not a big deal when it comes to a single page of the exercise, the purpose of the exercise is very much bound to the error analysis we perform afterwards, so we can identify what to adjust in our approach when next practicing the exercise. Without applying the line extensions in their entirety, we're working with partial information, which severely undermines what we stand to gain from it.

Moving onto your form-intersection-vehicles, you've done a solid job here. Many students mistake this exercise for something much more involved (and will often try to build up their forms while applying the constructing-to-scale approach, putting down a whole grid and all. What you've done here is exactly what was asked - just arranging the same primitives we use in the form intersection exercise in the layout of a vehicle, so we can remind ourselves that even though we're working with grids, we're still working with complete forms - not individual edges that get stitched together as needed. Focusing on the complete nature of these forms helps us maintain the focus on the process itself, how we're just combining forms bit by bit, and at all times have a solid structure (as opposed to the impression that until we reach the later phases, we've just got a mess of lines).

Continuing forward to your more detailed vehicle constructions, you continue to do a very good job. You're showing a great deal of patience and care, not only as you build out each structure, but also in observing and studying your references to identify exactly what it is you're building up. You're demonstrating a very strong capacity for keeping track of a lot of information (in terms of all the grid lines and subdivisions).

My only real critiques are somewhat superficial. The main thing I wanted to give you a reminder of is that in this course (specifically due to the tools we use, with the strict use of black/white and nothing in between), that when we leverage our filled areas of solid black, we do so only to capture cast shadows. I think you've largely demonstrated an awareness of this, but there were some little cases where you deviated from this.

For example, on this one, where you filled in the wheel well, and on this one where you filled in the gaps between the grill as well as the opposite wheels. Remember that a cast shadow is always going to require us to design the given shadow shape such that it establishes the relationship between the form casting the shadow, and the surface receiving it. It's rather easy if we're not keeping this in mind to end up filling in shapes/spaces that are already defined without the goal of defining that relationship, and when you catch yourself doing that, it's important to take a step back and ask yourself whether what you're filling in is really more form shading, or perhaps capturing a local surface colour, rather than actually establishing a shadow being cast.

Now, this primarily applies within this course (as a stylistic choice focused on helping students focus on the 3D/spatial aspect of the constructions), but it is still valuable to understand the differences between what we're actually capturing - whether it's a cast shadow, whether it's form shading, or whether we're simply seeing a dark area on the surface of the object, and trying to capture that without necessarily knowing whether it's the result of the interaction of 3D forms/light sources, or whether it's just a marking on the object.

Anyway, as a whole you've done a great job. Just be sure to review the line extensions instructions on the cylinder challenge. I'll go ahead and mark this lesson - and the course with it - as complete. Congratulations!